A prospective study examining the influence of cardiac rehabilitation on the sedentary time of highly sedentary, physically inactive patients.

OBJECTIVES: Prolonged sedentary time is recognized as a distinct health risk, and mortality risks are expected to be greatest for individuals with low exercise levels. It is unknown whether participation in exercise-based cardiac rehabilitation (CR) programs influences sedentary behaviour particularly among those patients expected to be at greatest mortality risk. This study examined the influence of CR participation on sedentary behaviour and identified the proportion and characteristics (socio-demographic and clinical) of patients who do not meet exercise recommendations and have prolonged sedentary times. METHODS: A prospective study was conducted among patients of an exercise-based CR program and assessments performed at baseline and 3 months. Physical activity and sedentary behaviour information were collected by self-report, and convergent validity was examined on an accelerometer-wearing subsample. RESULTS: Of 468 CR patients approached, 130 participants were recruited with an average sedentary time of 8hours/day. Sedentary behaviour remained consistent at follow-up (relative change= -2.4%, P=0.07) notwithstanding a greater proportion meeting exercise recommendations (relative change= 57.4%). 19.2% of participants were classified to have prolonged sedentary time and not meet exercise recommendations at baseline. No significant differences were found between the characteristics of high-risk individuals and lower risk subgroups. Findings were consistent among the accelerometer-derived subgroup and the overall sample despite poor to moderate convergent validity. CONCLUSIONS: These results suggest that the exercise-focus of CR may not reduce sedentary behaviours. Future studies are needed to determine whether sedentary behaviour-specific reduction strategies are more effective than traditional exercise-based strategies and lead to meaningful improvements in clinical outcomes.

Quality of life and psychosocial measures influenced by exercise modality in patients with coronary artery disease.

BACKGROUND: The optimal approach to prescribing resistance training (RT) combined with aerobic training (AT) for psychosocial and health-related quality of life (HRQOL) is unclear. AIM: To compare the effects of AT combined with RT (1 versus 3 sets) versus AT alone on HRQOL and psychosocial outcomes. DESIGN: Subjects (N.=72) were randomized to AT (5 d∙wk-1) or AT (3 d∙wk-1) with either 1 set (AT/RT1) or 3 sets (AT/RT3) of RT performed 2 d∙wk-1. SETTING: Outpatient Cardiac Rehabilitation Program. POPULATION: Subjects with coronary artery disease. METHODS: HRQOL and psychosocial parameters were assessed before and after 29 weeks of training by questionnaire. RESULTS: Fifty-three subjects (mean±SD age 60.6±10.6 years) completed training. There was a group effect for change in self-efficacy of lower body physical activity tasks (P=0.03) with significantly greater improvement for AT/RT3 than AT alone (17.5±16.6% vs. 3.2±12.8% respectively, p=0.04). Lower body self-efficacy improved for AT/RT1 (15.5±13.8%, p<0.001) but not for AT alone (P=0.2). Self-efficacy for upper body tasks improved with AT/RT3 (18.2±19.9%, P=0.003) and AT/RT1 training (12.6±15.8%, P=0.005) but not with AT alone (8.3±16.1%, P=0.1). AT/RT3 and AT/RT1 training yielded improvements in depression score (-4.0±7.7, P=0.04 and -3.0±5.1, P=0.02 respectively) but not with AT alone (-0.5±4.7, P=0.71). The improvement from baseline in physical HRQOL score (MOS, SF-36) averaged 8.2±11.2% for AT (P=0.04), 10.4±11.9% for AT/RT1 (P=0.006) and 12.0±12.9% for AT/RT3 (P=0.004). CONCLUSIONS: Both AT+RT groups with either 1 or 3 sets (AT 3 d∙wk-1and RT 2 d∙wk-1) each yield more pronounced psychosocial and HRQOL adaptations than AT alone (5 d∙wk-1). RT prescription beyond 1 set may further augment selected parameters in cardiac patients. CLINICAL REHABILITATION IMPACT: These results provide further rationale to develop combined AT+RT regimens for individuals with coronary artery disease.

Outcomes associated with cardiac rehabilitation participation in patients with musculoskeletal comorbidities.

BACKGROUND: Individuals with coronary artery disease (CAD) and musculoskeletal comorbidities (MSKCs) have much to gain from physical activity, yet are less likely to be referred to cardiac rehabilitation (CR) than those without MSKCs. Whether patients with MSKCs achieve demonstrated benefits of CR participation such as improved quantity and quality-of-life remains unknown. AIM: To compare all-cause mortality, major acute cardiovascular events (MACEs), quality-of-life and psychosocial well-being in patients with CAD and coexisting MSKCs by CR participation. DESIGN: Prospective and observational study in which patients were administered a questionnaire in the hospital and 1 year later. The cohort was linked to provincial databases. SETTING: Eleven hospitals in Ontario, Canada. POPULATION: CAD patients (N.=1680). METHODS: CAD inpatients were administered a questionnaire assessing sociodemographic and clinical characteristics. Clinical data were extracted from charts. CR participation, quality-of-life, depressive symptoms, functional status, and physical activity behavior were measured 1 year later by questionnaire. The cohort was linked to provincial administrative databases to ascertain mortality and MACEs for a median of 2.7 years post-index cardiac hospitalization. Associations of CR participation with outcomes were tested after adjustment for differences in participation propensity. RESULTS: Of study participants, 50.7% (851/1680) had MSKCs and of those with MSKCs, 49.8% (424/851) participated in CR. Patients with MSKCs who participated in CR had greater physical quality-of-life (P<0.03) and lower mortality than those with MSKCs who did not attend CR, after adjusting for propensity for CR participation (1.4% vs. 4%; participant vs. non-participants, P=0.03) - non-participants' hazard ratio 3.91 [95%CI,1.23-12.36]). There were no differences for MACEs. CONCLUSION: Among those with MSKCs, participation in CR is associated with survival benefit and better physical quality-of-life compared to non-participants. CLINICAL REHABILITATION IMPACT: Our findings showing the high prevalence of MSKCs in those with CAD and the benefits of CR, add to the literature that will provide the basis for exploration of initiatives to improve care for those with CAD and MSKC, and to overcome barriers to improved outcomes and reduced death. These results will help to guide focused research to optimize complex outpatient care in this group, including increasing the utilization of CR.

The economic burden of obesity worldwide: a systematic review of the direct costs of obesity.

In the last decade, the prevalence of obesity has increased significantly in populations worldwide. A less dramatic, but equally important increase has been seen in our knowledge of its effects on health and the burden it places on healthcare systems. This systematic review aims to assess the current published literature on the direct costs associated with obesity. A computerized search of English language articles published between 1990 and June 2009 yielded 32 articles suitable for review. Based on these articles, obesity was estimated to account for between 0.7% and 2.8% of a country's total healthcare expenditures. Furthermore, obese individuals were found to have medical costs that were approximately 30% greater than their normal weight peers. Although variations in inclusion/exclusion criteria, reporting methods and included costs varied widely between the studies, a lack of examination of how and why the excess costs were being accrued appeared to be a commonality between most studies. Accordingly, future studies must better explore how costs accrue among obese populations, in order to best facilitate health and social policy interventions.

The relationship between unprovoked venous thromboembolism, age, and acute myocardial infarction.

BACKGROUND: Patients with unprovoked venous thromboembolism (VTE) may be at increased risk of acute myocardial infarction (AMI). However, the nature and clinical significance of this association remain unclear, particularly as it relates to age of presentation. METHODS: We performed a longitudinal matched cohort study utilizing multiple administrative databases. Ontario residents aged 20-64 years diagnosed with unprovoked VTE from 1 April 1991 to 31 March 1995 (n = 6065) were matched to a population cohort (n = 12 040) in 1 : 2 fashion on the basis of age, gender, socioeconomic class, cardiovascular risk factors and other comorbidities. The primary outcome was a comparison of relative risk of AMI over 10-year follow-up in subjects with unprovoked VTE (overall and stratified by age) vs. controls. Secondary outcomes included risk of death or the composite endpoint of AMI and/or death. RESULTS: Patients 20-39 years of age presenting with unprovoked VTE had an increased risk of AMI [adjusted hazard ratio (HR) 3.92, 95% confidence interval (CI) 1.65-9.35] as compared to controls; the association was applicable to those without atherosclerotic risk factors at baseline. There was no significant relationship between unprovoked VTE and AMI among patients 40-64 years old, with or without atherosclerotic risk factors. Irrespective of age, patients with unprovoked VTE had an increased risk of all-cause death or our composite endpoint of AMI and/or death as compared to patients without VTE. CONCLUSIONS: Unprovoked VTE is associated with a nearly 4-fold higher risk of subsequent AMI among younger patient populations. Future studies must explore the risk-benefit tradeoffs of long-term surveillance and management options among such patient populations.

Age-social stratification designs had a negligible impact on income-mortality associations.

OBJECTIVES: Age-social stratification has been used to offset socioeconomic status (SES) misclassification due to cohort effects. This study was to evaluate whether age-income stratification designs generate comparable income-mortality associations as those whose income rankings are based on absolute thresholds. STUDY DESIGN AND SETTING: Using self-reported income as our SES variable, and mortality as our outcome measure, the impact of age-social stratification was examined in two distinct cohorts: one with acute myocardial infarction (AMI) (n=3,138), and the second free of cardiovascular disease (n=15,115). Age-adjusted income-mortality associations were compared between age-social stratification techniques, which used "age-relative" income thresholds and "absolute" income thresholds whose ranks were independent of patient age. RESULTS: In both cohorts, crude mortality inversely correlated with age and income. Techniques using "age-relative" income thresholds yielded similar adjusted odds ratio for mortality as did those that used "absolute" income threshold methods (differences in adjusted odds ratios [+/-95% confidence interval (CI)] between "absolute" and "age-relative" classifications for highest vs. lowest income tertiles: -0.05 [-0.24, 0.12] among patients with AMI and 0.05 [-0.03, 0.13] among patients without cardiovascular disease). CONCLUSION: More complex designs incorporating age-social stratification techniques generate similar income-mortality associations as more simplified approaches, which classified SES using absolute income thresholds.

The impact of implantable cardiac defibrillators for primary prophylaxis in the community: baseline risk and clinically meaningful benefits.

OBJECTIVE: To estimate the baseline risk of arrhythmic death required for prophylactic implantable cardiac defibrillators (ICDs) to result in clinically meaningful survival benefits in the population. BACKGROUND: While proven efficacious, the absolute survival impact of ICDs for the primary prevention of sudden cardiac death among patients with left ventricular (LV) dysfunction is highly dependent upon patient's baseline risk of arrhythmic death. METHODS: Using echocardiographic data from a random sample of patients identified from community echocardiographic laboratories, patients with moderate or severe LV dysfunction (ejection fraction < 35%) were linked to administrative databases to characterize baseline mortality risk (median follow-up duration of 4.85 years). Relative efficacy was ascertained from meta-analysis and clinical trial data. The baseline annual risk of arrhythmic death required for prophylactic ICDs to result in clinically meaningful survival benefits in the population was estimated at different ranges of relative efficacy and numbers needed to treat (NNTs) thresholds. RESULTS: LV dysfunction was a significant independent predictor of adverse outcomes. In total, 35.4% of the patients with moderate to severe LV dysfunction died during the follow-up period. Assuming a base-case relative efficacy of 66%, we estimated that the baseline risk for arrhythmic death required to exert a clinically meaningful NNT threshold of 50 in order to prevent one death (from any cause) was 3% per year or higher. CONCLUSIONS: The survival impact and cost-effectiveness of prophylactic ICDs in the population will depend upon the ability to risk-stratify and identify patients whose baseline risk for sudden cardiac death exceed 3% per year.

The evaluation of a formalized queue management system for coronary angiography waiting lists.

BACKGROUND: Lengthy waiting lists for coronary angiography have been described in many health care systems worldwide. The extent to which formal queue management systems may improve the prioritization and survival of patients in the angiography queue is unknown. OBJECTIVE: To prospectively evaluate the performance of a formal queue management system for patients awaiting coronary angiography in Ontario. METHODS: The coronary angiography urgency scale, a formal queue management system developed in 1993 using a modified Delphi panel, allocates recommended maximum waiting times (RMWTs) in accordance with clinical necessity. By using a provincial clinical registry, 35,617 consecutive patients referred into the coronary angiography queue between April 1, 2001, and March 31, 2002, were prospectively tracked. Cox proportional hazards models were used to examined mortality risk across urgency after adjusting for additional clinical and comorbid factors. RESULTS: Good agreement was determined in urgency ratings between scores from the coronary angiography urgency scale and implicit physician judgement, which was obtained independently at the time of the index referral (weighted kappa = 0.49). The overall mortality in the queue was 0.3% (0.47%, 0.26% and 0.13% for urgent, semiurgent and elective patients, respectively). Urgency, as specified by the coronary angiography urgency scale, was the strongest predictor of death in the queue (P<0.001). However, when patients were censored according to their RMWTs, mortality was similar across different levels of urgency. Consequently, up to 18.5 deaths per 10,000 patients could have potentially been averted had patients been triaged and undergone coronary angiography within the RMWT as specified by the coronary angiography urgency scale. CONCLUSIONS: The incorporation of the coronary angiography urgency scale as a formal queue management system may decrease mortality in the coronary angiography queue. The authors recommend its implementation in health care systems where patients experience excessive waiting time delays for coronary angiography.

Utilisation of coronary angiography after acute myocardial infarction in Ontario over time: have referral patterns changed?

OBJECTIVE: To examine how physicians in Ontario, Canada, have altered their referral patterns for coronary angiography after acute myocardial infarction (AMI) over time. DESIGN: Retrospective analysis of multilinked administrative data. SETTING: Province of Ontario, Canada. PATIENTS: 146 365 Ontario AMI patients hospitalised between 1 April 1992 and 31 March 1999. MAIN OUTCOME MEASURES: Utilisation trends of coronary angiography among all patients, as well as within six subgroups: elderly (versus young), women (versus men), high (versus low) risk of 30 day mortality, high (versus low) socioeconomic status, cardiology (versus non-cardiology) attending physician specialty, and hospitals with (versus without) onsite revascularisation capacity. Cox proportional hazard models were adjusted for variations in patient, physician, and hospital characteristics over time. RESULTS: Angiography rates in Ontario increased from 23.2% in 1992 to 35.5% in 1999 (p < 0.0001). Increases in utilisation of coronary angiography were most pronounced among the elderly (12.4-24.3% v 39.3-54.4% for non-elderly patients, p < 0.0001), the affluent (24.6-38.7% v 22.0-32.3% for less affluent patients, p = 0.01), and those tended to by cardiologists (32.0-47.1% v 20.3-30.1% for non-cardiology attending specialties, p < 0.0001) after adjusting for changes in baseline patient, physician, and hospital characteristics over time. CONCLUSIONS: Despite universal health care availability, not all patients benefited equally from increases in service capacity for coronary angiography after AMI in Ontario. Wider implementation of data monitoring and explicit management systems may be required to ensure that appropriate utilisation of cardiac services is allocated to patients who are most in need.

Biology or bias: practice patterns and long-term outcomes for men and women with acute myocardial infarction.

OBJECTIVES: The goal of our study was to examine how age and gender affect the use of coronary angiography and the intensity of cardiac follow-up care within the first year after acute myocardial infarction (AMI). Another objective was to evaluate the association of age, gender and treatment intensity with five-year survival after AMI. BACKGROUND: Utilization rates of specialized cardiac services inversely correlate with age. Gender-specific practice patterns may also vary with age in a manner similar to known age-gender survival differences after AMI. METHODS: Using linked population-based administrative data, we examined the association of age and gender with treatment intensity and long-term survival among 25,697 patients hospitalized with AMI in Ontario between April 1, 1992, and December 31, 1993. A Cox proportional hazards model was used to adjust for socioeconomic status, illness severity, attending physician specialty and admitting hospital characteristics. RESULTS: After adjusting for baseline differences, the relative rates of angiography and follow-up specialist care for women relative to men, respectively, fell 17.5% (95% confidence interval [CI], 13.6 to 21.3, p < 0.001) and 10.2% (95% CI, 7.1 to 13.2, p < 0.001) for every 10-year increase in age. Conversely, long-term AMI survival rates in women relative to men improved with increasing age, such that the relative survival in women rose 14.2% (95% CI, 10.1 to 17.5, p < 0.001) for every 10-year age increase. CONCLUSIONS: Gender differences in the intensity of invasive testing and follow-up care are strongly age-specific. While care becomes progressively less aggressive among older women relative to men, survival advantages track in the opposite direction, with older women clearly favored. These findings suggest that biology is likely to remain the main determinant of long-term survival after AMI for women.

Long-term MI outcomes at hospitals with or without on-site revascularization.

CONTEXT: Many studies have found that patients with acute myocardial infarction (AMI) who are admitted to hospitals with on-site revascularization facilities have higher rates of invasive cardiac procedures and better outcomes than patients in hospitals without such facilities. Whether such differences are due to invasive procedure rates alone or to other patient, physician, and hospital characteristics is unknown. OBJECTIVE: To determine whether invasive procedural rate variations alone account for outcome differences in patients with AMI admitted to hospitals with or without on-site revascularization facilities. DESIGN: Retrospective, observational cohort study using linked population-based administrative data from a universal health insurance system. SETTING: One hundred ninety acute care hospitals in Ontario, 9 of which offered invasive procedures. PATIENTS: A total of 25 697 patients hospitalized with AMI between April 1, 1992, and December 31, 1993, of whom 2832 (11%) were in invasive hospitals. MAIN OUTCOME MEASURES: Mortality, recurrent cardiac hospitalizations, and emergency department visits in the 5 years following the index admission, adjusted for patient age, sex, socioeconomic status, illness severity, and index revascularization procedures; attending physician specialty; and hospital volume, teaching status, and geographical proximity to invasive-procedure centers and compared by hospital type. RESULTS: Patients admitted to invasive-procedure hospitals were much more likely to undergo revascularization (11.4% vs 3.2% at other hospitals; P<.001). However, many other clinical and process-related factors differed between the 2 groups. Although mortality rates were similar between the 2 institution types, the nonfatal composite 5-year event rate (ie, recurrent cardiac hospitalization and emergency department visits) was lower for patients initially admitted to invasive-procedure hospitals (71.3% vs 80.4%; unadjusted odds ratio [OR], 0.65; 95% confidence interval [CI], 0.52-0.82; P<.001). This advantage persisted after adjustment for sociodemographic and clinical factors and procedure utilization (adjusted OR, 0.68; 95% CI, 0.53-0.89; P<.001). However, the nonfatal outcome advantages of invasive-procedure hospitals were explained by their teaching status (adjusted OR, 0.98; 95% CI, 0.73-1.30; P =.87). CONCLUSIONS: In this sample of patients admitted with AMI, the differing outcomes of apparently similar patients treated in 2 different practice settings were explained by multiple competing factors. Researchers conducting observational studies should be cautious about attributing patient outcome differences to any single factor.

Effects of socioeconomic status on access to invasive cardiac procedures and on mortality after acute myocardial infarction.

BACKGROUND: Universal health care systems seek to ensure access to care on the basis of need rather than income and to improve the health status of all citizens. We examined the performance of the Canadian health system with respect to these goals in the province of Ontario by assessing the effects of neighborhood income on access to invasive cardiac procedures and on mortality one year after acute myocardial infarction. METHODS: We linked claims for payment for physicians' services, hospital-discharge abstracts, and vital-status data for all patients with acute myocardial infarction who were admitted to hospitals in Ontario between April 1994 and March 1997. Patients' income levels were imputed from the median incomes of their residential neighborhoods as determined in Canada's 1996 census. We determined rates of use and waiting times for coronary angiography and revascularization procedures after the index admission for acute myocardial infarction and determined death rates at one year. In multivariate analyses, we controlled for the patient's age, sex, and severity of disease; the specialty of the attending physician; the volume of cases, teaching status, and on-site facilities for cardiac procedures at the admitting hospital; and the geographic proximity of the admitting hospital to tertiary care centers. RESULTS: The study cohort consisted of 51,591 patients. With respect to coronary angiography, increases in neighborhood income from the lowest to the highest quintile were associated with a 23 percent increase in rates of use and a 45 percent decrease in waiting times. There was a strong inverse relation between income and mortality at one year (P<0.001). Each $10,000 increase in the neighborhood median income was associated with a 10 percent reduction in the risk of death within one year (adjusted hazard ratio, 0.90; 95 percent confidence interval, 0.86 to 0.94). CONCLUSIONS: In the province of Ontario, despite Canada's universal health care system, socioeconomic status had pronounced effects on access to specialized cardiac services as well as on mortality one year after acute myocardial infarction.

Fairness in the coronary angiography queue.

BACKGROUND: Since waiting lists for coronary angiography are generally managed without explicit queuing criteria, patients may not receive priority on the basis of clinical acuity. The objective of this study was to examine clinical and nonclinical determinants of the length of time patients wait for coronary angiography. METHODS: In this single-centre prospective cohort study conducted in the autumn of 1997, 357 consecutive patients were followed from initial triage until a coronary angiography was performed or an adverse cardiac event occurred. The referring physicians' hospital affiliation (physicians at Sunnybrook & Women's College Health Sciences Centre, those who practice at another centre but perform angiography at Sunnybrook and those with no previous association with Sunnybrook) was used to compare processes of care. A clinical urgency rating scale was used to assign a recommended maximum waiting time (RMWT) to each patient retrospectively, but this was not used in the queuing process. RMWTs and actual waiting times for patients in the 3 referral groups were compared; the influence clinical and nonclinical variables had on the actual length of time patients waited for coronary angiography was assessed; and possible predictors of adverse events were examined. RESULTS: Of 357 patients referred to Sunnybrook, 22 (6.2%) experienced adverse events while in the queue. Among those who remained, 308 (91.9%) were in need of coronary angiography; 201 (60.0%) of those patients received one within the RMWT. The length of time to angiography was influenced by clinical characteristics similar to those specified on the urgency rating scale, leading to a moderate agreement between actual waiting times and RMWTs (kappa = 0.53). However, physician affiliation was a highly significant (p < 0.001) and independent predictor of waiting time. Whereas 45.6% of the variation in waiting time was explained by all clinical factors combined, 9.3% of the variation was explained by physician affiliation alone. INTERPRETATION: Informal queuing practices for coronary angiography do reflect clinical acuity, but they are also influenced by nonclinical factors, such as the nature of the physicians' association with the catheterization facility.

A survey of provider experiences and perceptions of preferential access to cardiovascular care in Ontario, Canada.

BACKGROUND: The public health insurance system in Canada is predicated on equal access to care for persons in need. OBJECTIVE: To determine the views and experiences of Ontario physicians and hospital administrators in providing patients with preferential access to specialized cardiovascular care on the basis of nonclinical factors. DESIGN: Survey with self-administered questionnaire. SETTING: Ontario, Canada. PARTICIPANTS: All Ontario cardiologists (n = 268), cardiac surgeons (n = 68), and hospital chief executives (n = 218) and random samples of internists (n = 300) and family physicians (n = 300). MEASUREMENTS: Elicited responses (yes or no) to questions on whether and why preferential access occurred and whether the respondents had been personally involved in such a situation. RESULTS: After undeliverable surveys and respondents no longer involved with acute care were excluded, the eligible response rate was 71.3% (788 of 1105 respondents). More than 80% of physicians and 53% of hospital chief executives had been personally involved in managing a patient who had received preferential access on the basis of factors other than medical need. Patients deemed most likely to receive such treatment were those with personal ties to the treating physicians (93% [95% CI, 91% to 95%]), high-profile public figures (85% [CI, 82% to 87%]), and politicians (83% [CI, 80% to 86%]). Physicians were significantly more likely than chief executives to indicate that hospital board members (81% and 68%; P < 0.001) and donors to hospital foundations (63% and 42%; P < 0.001) would receive preferential access. Most respondents indicated that preferential access was more likely to be provided if patients or families were well informed, aggressive, or potentially litigious. The survey did not permit estimation of the frequency of episodes of preferential access. CONCLUSIONS: Although equality of access is a cornerstone principle of Canada's universal health care system, some access to specialized cardiovascular services occurs preferentially on the basis of factors other than clinical need. The actual magnitude and consequences of this phenomenon remain unknown.